I am using the MS word “find and replace” function (primitive, I know) to count the aliases of the players / GM. This means that this approach is prone to some (positive) error (because if someone mentions “Vlad” in an OOC, Vlad gets +1 post). However, comparison between the actual number of posts (via forum counter) and the “assumed” number of posts (via MS word) shows that the error is probably small enough to be ignored.